GB461362A - Improvements in and relating to valves for use in fluid pumps - Google Patents

Abstract

461,362. Fluid - actuated valves. HORSTMANN, S. A., and HORSTMAN, Ltd. Oct. 8, 1935, No. 27806. [Class 135] A byepass valve for fluid pumps designed to remain open after the pump delivery pressure has fallen below that required to open the valve has a series of radial passages 24 in the valve member or head 14, the fluid flow past the ends of which sets up an ejector action when the valve is open so as to reduce the pressure inside the valve stem 15 below that on the inlet side of the valve head. The valve may be used to byepass a petrol pump when a trigger or other valve in the delivery pipe is closed. The valve 14, Fig. 2, is loaded by a spring 19 adjustable by a screw 21 mounted in a cap 18. A cap 22 conceals the outer end of the screw 21. The hollow valve stem 15 is grooved externally and is guided in a tubular member 16 held together with the cap 18 in a part 17 of the pump casing. The member 16 and cap 18 are clamped in place so as to be readily removable by a V-shaped clamping member 25 positioned by a bolt 26. The valve member has a cylindrical part 14a projecting into the orifice of the seat 10. The interior of the stem 15 communicates with the pump delivery chamber 12 by a passage 23 enlarged at one end. The passage 23 may however be dispensed with and the part 14a or the passages 24 modified to allow fluid to pass through them to the interior of the stem. In cases where the effective areas provided on the two sides of the valve head 14 are such that the inlet pressure would rise unduly before the valve opens, the interior of the piston is placed in communication with the pump suction chamber 13 before this pressure is attained by a spring loaded ball or other valve 28. As shown in Fig..4, the valve 28 is arranged in the pump housing 17, but it may be carried by the stem 15.